### Project 18 Somebody is in this area

**1.Introduction**

In this lesson, we will combine PIR Motion Sensor, 1602 I2C Module and Piranha LED Module to make a device to detect whether there is someone or some animals around. The principle of this experiment can be applied in automatic switch of corridor light and burglar alarm etc.

**2.Hardware required**

- EASY plug controller Board *1
- USB cable *1
- EASY plug cable *3
- EASY plug Piranha LED Module *1
- EASY plug 1602 I2C Module *1
- EASY plug PIR Motion Sensor *1

Below is a brief introduction of EASY plug PIR Motion Sensor.

![](media/image-20251126154445000.png)

Pyroelectric infrared motion sensor can detect infrared signals from a moving person or moving animal, and outputs switching signals. It has advantages of low power consumption, good concealing, low cost etc. It can be applied to a variety of occasions to detect the movement of human body. Below are its specifications:

- Input Voltage: 3.3 ~ 5V, 6V Maximum
- Working Current: 15uA
- Working Temperature: -20 ~ 85 ℃
- Output Voltage: High 3V, low 0V
- Output Delay Time (High Level): About 2.3 to 3 Seconds
- Detection angle: 100 °
- Detection distance: 7 meters
- Output Indicator LED (When output HIGH, it will be ON)
- Pin limit current: 100mA
- Size: 36.4*20mm
- Weight: 4g

**3.Connection Diagram**

Now, connect the LED module to the D10 port of the controller board, motion sensor module to D3, and LCD module to IIC port using the EASY plug cables.

![](media/image-20251126154553736.png)

**4.Sample Code**

Connect the board to your PC using the USB cable; copy below code into Arduino IDE, and click upload to upload it to your board.

```c
#include <Wire.h>  // place file “Wire.h” under the “library” directory of Arduino 
#include <LiquidCrystal_I2C.h> // place file “LiquidCrystal_I2C.h” under the “library” directory of Arduino 
#define sensorPin 3
#define indicator 10
LiquidCrystal_I2C lcd(0x27,16,2);  // set the LCD address to 0x27 for a 16 chars and 2 line display

void setup()
{
  pinMode(sensorPin,INPUT);
  pinMode(indicator,OUTPUT);
  lcd.init();                      // initialize the lcd 
  lcd.init();
  // Print a message to the LCD.
  lcd.backlight();
}


void loop()
{
  byte state = digitalRead(sensorPin);
  digitalWrite(indicator,state);
  if(state == 1)
  {
  lcd.setCursor(2,0);
  lcd.print("Somebody is");
  lcd.setCursor(2,1);
  lcd.print("in this area!");
  }
  else if(state == 0)
  {
   lcd.setCursor(2,0);
  lcd.print("  No one!    ");
  lcd.setCursor(2,1);
  lcd.print("  No one!    ");
  }
  delay(500);
}
```

**5.Result**

After power is on, when there is no movement near the motion sensor, LCD displays “no one”, and piranha LED is off; when there is someone moving near the motion sensor, LCD will display “somebody is in this area!”, and the LED will be turn on.

![](media/image-20251126154652967.png)